This invention relates generally to the field of stairs and risers and more specifically to a machine for constructing height-adjustable stair steps.
U.S. Pat. No. 6,516,574 B1 by Couture discloses a staircase having metallic stringers, one of which is typically secured to half timbering, having temporary steps that are replaced later with permanent steps, and a vertical support attached to a framework by at least one horizontal support.
In substantial contrast to Couture, the instant art comprises no stringers, no vertical support attached to the framework of a building, and requires no temporary components.
U.S. Pat. No. 4,881,351 by Hamm discloses a staircase having U-shaped linking elements and steps attached to the linking elements by means of clamping joints. In addition, the erection of above disclosed staircase requires the on site drilling of holes.
In contrast to Hamm, the instant art requires no U-shaped elements and no clamping joints. In additional contrast to Hamm, the instant art requires no on site modifications.
U.S. Pat. No. 5,123,210 by Schmidt teaches a flight of stairs having a bottom step and a top step, both resting on an intermediate floor, a landing beam, or similar member. In addition, Schmidt also teaches at least one lateral end of each step arranged within a square support consisting of two horizontal and two vertical members, which, together, form a stair stringer in such manner that each step is supported by the assigned horizontal member beneath it, and such that each horizontal member extends beyond a vertical member which passes through the horizontal member, so that the extension of the upper horizontal member forms the lower horizontal member of the next step above it, while the extension of the lower horizontal member forms the upper horizontal member of the next step beneath it.
In contrast to Schmidt, the instant art teaches no bottom step or top step resting on an intermediate floor or any other member. In additional contrast to Schmidt, the instant art comprises no square support structure nor any arrangement wherein horizontal members comprise portions of two different steps nor any arrangement wherein vertical members pass through horizontal members.
U.S. Pat. No. 6,318,033 B1 by Birch et al. teaches a staircase repair device requiring an existing staircase and a new staircase construction having a plurality of stair tread members spanning between standard stringers.
In contrast to Birch et al., the instant art requires no existing staircase. In additional contrast to Birch et al., the instant art neither teaches nor requires standard stringers.
U.S. Pat. No. 5,502,933 by Skillern discloses a staircase construction comprising modules having a vertically oriented rectangular front member, a vertically oriented rectangular back member, a first horizontally oriented assembly diaphragm connecting a top of said back member to a top of said front member which diaphragm either serves as a step or supports a covering used as a step, and right and left side members attached to vertical ends of said front and back members. In addition, Skillern teaches one embodiment having a modular staircase supported by an underlying framework and one embodiment having a free standing staircase comprising modules with flanged support members connecting the front portion of a module to the rear portion of a module.
In contrast to Skillern, the instant art teaches no rectangular panels which support a step. In additional contrast to Skillern, the instant art requires no diaphragm member to connect the top of a front member to the front of a back member. In yet further contrast to Skillern, the instant art neither teaches nor requires an underlying framework nor flanged support members connecting the front portion of the module to the rear portion of the module.
U.S. Pat. No. 4,041,662 by Ward discloses a staircase construction having modules comprising brackets having four substantially parallel surfaces oriented substantially horizontally with the modules bolted together by means of vertically oriented holes in the substantially parallel surfaces which must be caused to align.
In contrast to Ward, the instant art teaches only one substantially horizontal surface. In further contrast to Ward, the instant art teaches no joining of modules by means of vertically oriented holes with bolts therethrough. In yet additional contrast to Ward, the instant art teaches joining of modules by means of brackets communicating with two surfaces rather than four.
U.S. Pat. No. 5,014,475 by Anderson, Jr. et al. teaches a staircase construction comprising modules bolted together and supported by stringers or by a stringer and another surface such as a wall. In addition, Anderson, Jr. et al. teach a tread portion which meets a riser portion to form a nosing, and a shoulder attached to the riser to support the tread portion.
In contrast to Anderson, Jr. et al., the instant art neither teaches nor requires stringers or other support structures. In additional contrast to Anderson, Jr. et al., the instant art neither teaches nor requires a tread portion to meet a riser portion to form a nosing nor a shoulder attached to the riser to support the tread portion.
U.S. Pat. No. 5,720,136 by Turner discloses a stairway construction comprising modules connected together to form a box beam with all modules connected by a longitudinal tension member to prevent separation of the modules under weight. In addition, Turner requires construction of the staircase from the bottom up and the addition of tread members as the last construction step after all modules have been connected.
In contrast to Turner, the instant art requires no box beam configuration nor any continuous longitudinal member communicating with all modules. In additional contrast to the instant art, since Turner teaches installation of tread elements and the longitudinal member on site after all modules are connected, the Turner modules cannot be fully assembled beforehand. This increases the time and labor required on site. The instant art overcomes this limitation. In further contrast to Turner, the instant art is not limited to construction from the ground up.
U.S. Pat. No. 4,838,005 by Graham et al. discloses a staircase construction having stringer elements and tread pan elements into which a flowable material such as concrete is poured to form a tread portion. Also, Graham et al. teaches welding together of stringers and tread pan riser elements.
In contrast to Graham et al., the instant art neither teaches nor requires stringer elements nor the pouring of any flowable material. In additional contrast to Graham et al., the instant art does not teach the limitation of welding to connect tread and/or riser units to any other elements.
U.S. Pat. No. 705,794 by Snider teaches a spiral or curved staircase construction having pipes and various socketed pipe connectors configured as flange sockets, L-sockets, or T-sockets.
In contrast to Snider, the instant art is not limited to spiral or curved staircase construction. In further contrast to Snider, the instant art is not limited to pipe construction and comprises no socketed elements.
U.S. Pat. No. 1,547,254 by McClure discloses a spiral stairway having a central column.
In contrast to McClure, the instant art is not limited to spiral stairway construction. In further contrast to McClure, the instant art neither teaches nor requires a central column.
U.S. Pat. No. 4,850,164 by McLeod discloses a stair construction having at least one stringer having a plurality of treads supported on the stringer. In addition, McLeod teaches that the stringer must be capable of being trimmed away either in a manner that would alter the dimensions of the staircase or in a manner that would not alter the continuity of the shape of the staircase.
In contrast to McLeod, the instant art neither teaches nor requires a plurality of treads to communicate with one stringer. In additional contrast to McLeod, the instant art requires no trimmable elements.
U.S. Pat. No. 990,701 by Burge describes a structure of the fire escape classification and class with one side attached to a wall. In addition, Burge teaches rails from which are suspended hangers which support cross rods. Also, Burge teaches a sheet of flooring material extending over some cross rods and below others.
In contrast to Burge, the instant art is not limited to fire escapes and is not limited to being attached to a wall or any other building structure. In additional contrast to Burge, the instant art is not supported by or suspended from rails and neither teaches nor requires any sheet to pass over some cross elements and under others.
U.S. Pat. No. 3,556,251 by Whitehead discloses a prefabricated staircase having at least one parallelogram truss having an upper chord and a lower chord. The upper chord comprises holes for pivot points which support a plurality of panel members. In addition, the upper chord provides stiffness to resist compression as the staircase bears weight. The lower chord has holes for pivot points situated at intervals to correspond with those in the upper chord so that the lower chord can support panel members. The lower chord also provides resistance to tension caused by a load on the staircase.
In contrast to Whitehead, the instant art teaches no element to support a plurality of panels nor any continuous elements to bear stress. In addition, the instant art neither teaches nor requires any elements to pivot in relation to any others.
U.S. Pat. No. 4,798,030 by Molinazzi teaches a modular support for staircase steps having a box-like body with a male portion and a female portion on opposite sides whereby individual modules communicate. Molinazzi also teaches a first headpiece extending from the male portion upon which a step may be mounted and a second headpiece extending from the male portion at the end opposite the first headpiece so that when male and female portions communicate, screws can be inserted vertically through the headpieces of the male portion into the female portion of a communicating module to hold both together. In addition, Molinazzi teaches tooth means projecting from the male portion and the female portion, by which connection angles may be selected.
In contrast to Molinazzi, the instant art neither teaches nor requires male and/or female elements to affect communication between modules. In further contrast to Molinazzi, the instant art comprises no head pieces or tooth means and requires no vertical screws to join modules together.
U.S. Pat. No. 4,516,367 by Molinazzi discloses a modular support for stairway steps comprising cylindrical elements having convex sides and concave sides whereby the cylindrical elements communicate. In addition, Molinazzi teaches clamping elements to hold communicating cylindrical elements together.
In contrast to Molinazzi, the instant art is not limited to cylindrical elements, neither teaches nor requires communication between convex and concave elements, and neither teaches nor requires any clamping elements.
U.S. Pat. No. 4,520,897 by Gebo teaches portable steps supported by and in contact with the ground and using spikes to attach the steps directly to the ground.
In contrast to Gebo, the instant art neither teaches nor requires that the steps contact the ground and requires no spikes to attach steps directly to the ground.
U.S. Pat. No. 4,296,577 by Schuette and U.S. Pat. No. 4,373,609 by De Donato disclose stringers which support stair treads.
In contrast to Schuette and De Donato, the instant art neither teaches nor requires stringers.
U.S. Pat. No. 3,474,882 by Ernst teaches a stringer structure for supporting a staircase, scaffold, or similar structure.
In contrast to Ernst, the instant art neither teaches nor requires stringers.